Qt is the fundamental technology that the G System is based on. Qt is a cross plattform C++ toolkit with many advanced features, bringing C++ development to an even higher level.

You need to know Qt for both, using the G System Framework to build your own applications as well as for developing the G System itself.

Qt is developed by Trolltech and freely available for all plattforms for use with open source projects. Trolltech also provides the source code for Qt. KDE, a powerful desktop environment, is also based on Qt.

You can learn about Qt on http://doc.trolltech.com. The currently used version is 4.1 since the G System 0.6 release. The old 0.5 version of the G System uses version 3.3 of Qt. It is recommended to learn about Qt4 and not Qt3 of course, unless you have to deal with older G System versions.

It is highly recommended to work through the provided tutorials.

There is an independent Qt tutorial available which is also a very good resource for learning Qt.

Qt is based on C++, this means you should also be familiar with C++ itself and should be aware of the C++ syntax and general object orientated programming (OOP) concepts. There is a good freely available online-book available, Thinking in C++ (TICPP): http://www.briceg.com/ticpp/one/, you only need to read book one, the second covers many aspects that you do not need for the G System.